Wired News: Fantastic Voyage: Departure 2009:
"An international team of scientists is developing what they say will be the world's first microrobot -- as wide as two human hairs -- that can swim through the arteries and digestive system.
The scientists are designing the 250-micron device to transmit images and deliver microscopic payloads to parts of the body outside the reach of existing catheter technology.
It will also perform minimally invasive microsurgeries, said James Friend of the Micro/Nanophysics Research Laboratory at Australia's Monash University, who leads the team. The researchers hope the device will reduce the risks normally associated with delicate surgical procedures.
While others have tried and failed to create microrobots for arterial travel, Friend believes his team will succeed because they are the first to exploit piezoelectric materials -- crystals that create an electric charge when mechanically stressed -- in their micromotor design.
'People have tried various techniques, including electromagnetic motors,' Friend said. 'But at this scale, electromagnetic motors become impractical because the magnetic fields become so weak. No one has taken the trouble to build piezoelectric motors at the same scales, for this kind of application.'"